<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>test</title>
    <script>
        }
    </script>
</head>
<body>
    <button id="btn1" value="btn" >
        btns
    </button>
    <div id="test">
        <h1>hello world</h1>
    </div>

</body>
</html>